Exploration of Hydrogeochemical Characterization and Assessment of Organic Pollution Characteristics of Shallow Groundwater near a Chemical Plant That Discharged Sewage Illegally

Groundwater plays a significant role in domestic use and agricultural irrigation in rural areas of northern China. The untreated wastewater from the chemical plant was directly discharged into a seepage well, resulting in the pollution of groundwater. Assessing characteristics of groundwater organic pollution and identifying evolutionary mechanisms of hydrogeochemistry are beneficial for groundwater protection and sustainable management. Statistical methods (correlation analysis (CA) and principal component analysis (PCA)) combined with hydrogeochemical methods including Piper, Gibbs, Gaillardet, and ions binary diagrams and the chloride alkalinity index were employed to explore hydrogeochemical characteristics and evolutionary mechanisms. The results showed that cations were predominantly located at the Ca2+ end and anions were mostly close to the SO42− and Cl− end. The ion concentrations of groundwater were mainly affected by water–rock interactions. The weathering or dissolution of silicate (i.e., aluminosilicate minerals), evaporite (i.e., halite and gypsum), carbonate minerals (i.e., calcite and dolomite), cation exchange, and anthropogenic activities contribute to the chemical compositions of groundwater. Based on CA and PCA, the dissolution of halide minerals and the use of pesticides and fertilizers were the main factors controlling water chemistry. Additionally, the dissolution of sulfur-bearing minerals and gypsum was the key factor controlling the concentrations of Ca2+ and Mg2+. Application of mathematical statistical methods characterized that the exceedance rate of seven organic compounds with high detection rates were as follows: carbon tetrachloride (39.83%) > 1,1,2-trichloroethane (28.81%) > chloroform (10.17%) > trichloroethene (6.78%) > 1,1,2,2-tetrachloroethane (5.93%) > perchloroethylene (5.08%) > trichlorofluoromethane (0.85%). Simultaneously, pollution under the influence of volatilization and diffusion was significantly less than that in the direction of groundwater runoff.

Operation mode evaluation in aerosol hot fog generator robotic system in orchard

The article presents a self-propelled aerosol hot fog generator robotic platform developed at the All-Russian Research Institute of Agricultural Mechanisation. The study aimed to assess the distribution quality of hot fog in the fruit tree crown during technological plant protection procedures and to determine the platform’s effective motion modes. Field studies established the causes of chemicals loss during technological plant protective measures in the crown. We determined the effect of droplet size on leaf cover density and plotted the solution droplet penetration into the crown. In field experiments, we plotted the crown permeability by aerosol in transverse projection. A statistical analysis of factorial trials of the fog generator robotic platform for chemical plant protection revealed its most effective operation modes as follows: robotic platform speed 2.1 km/h, fog nozzle -- tree crown distance 1.28 m, working fluid flow rate 39.75 L/h. One-pass droplet density in equal penetration plane crossing the inter-row axis is 480 pcs/cm2. The row treatment from the other side doubles the droplet estimate. The study pinpoints and verifies advantages of the developed aerosol hot fog generator robotic platform in an orchard setting. The field data analyses suggest that this robotic system meets the technological requirements of fluid chemical plant protection at a high standard level.

Forecasting the time stock for chemical plant protection based on computer simulations

The approach, algorithm, and intelligent system of support of decision-making of management for forecasting of time fund for the performance of the mechanized chemical protection of plants are offered. They are based on the formation of a database and knowledge of the weather from the Open Weather Map service for individual countries and their regions. They provide the formation of databases and knowledge for a given country or its region, taking into account the characteristics of natural, climatic, and industrial conditions based on computer modelling. Also, the proposed intelligent management decision support system provides a systematically accountable set of variable agrometeorological components of the mechanized chemical plant protection system and their impact on the projected time fund of the relevant work. Based on the use of the developed intelligent system of support of acceptance of administrative decisions forecasting of time fund for the performance of the mechanized chemical protection of plants and the set natural-climatic and industrial conditions is executed. The climatically admissible time fund model for mechanized chemical protection of plants during the day for May, which is described by Weibull distribution, is substantiated. The obtained research results can be used by managers of agricultural enterprises during the management processes of forecasting the time fund for the implementation of mechanized chemical plant protection. The developed intelligent decision support system provides further research on forecasting the time fund for the implementation of mechanized chemical plant protection and substantiation of its models for different countries and their regions.

Analysis of Explosion Accidents in a Chemical Plant using STAMP, a Systematic Cause-and-effect Analysis Technique

The process safety management system for chemical plants was introduced approximately 25 years ago. With the improvement in the safety management levels for the safe operation of the chemical plants, the number of serious industrial accidents has gradually decreased; however, increased damages have been observed when accidents do occur. The cause of accidents has also increased in cases where several factors, including social and cultural factors, are complexly related, in addition to facility and human factors. The need for an overall integrated systemic approach related to society, technology, and organization, and a sequential approach for finding the direct cause of accidents, is growing while analyzing the accidents. For this reason, foreign countries have introduced and applied a method to analyze accidents in an integrated manner from a systemic point of view; however, reports of cases or research results used in Korea. In this study, the case of explosion accidents, which occurred during a trial operation at a domestic chemical plant, was analyzed using Systems-Theoretic Accident Model and Processes, a systematic accident analysis technique, to reveal the primary cause, organizational, and operational problems, so that it can be used for future investigations when other accidents occur.

Hygienic evaluation of the most common methods of agricultural crops treatment with chemical protection products (literature review)

Global strategies, including application of chemical plant protection products, are important in the cultivation of safe corps and preservation of human health. A promising area of preventive medicine, agronomy, agroecology and agroengineering is the optimization of methods of pesticide formulations application. The aim of the work was a hygienic assessment of the most common and latest methods of crops treatment with chemical pesticides. Results. The biological effectiveness of different types of pesticides is achieved by different application rates of the working solution. The most common method of pesticide application is spraying, which ensures the application of pesticides in the drop-liquid state and is characterized by low consumption of active substance per unit area, variable-controlled distribution on the treatment surface, provides good adhesion and retention on facilities, allows the use of combined formulations. One of the most effective ways to minimize the negative impact of chemical plant protection products and achieve economic success is a rational approach to the choice of pesticide application, as it takes into account the hazard class of pesticides, the presence of water protection zones, the sensitivity of target crops, etc. Conclusion. Rational application of pesticides includes minimizing the overall effect of pesticides on human health and the environment and achieving high-targeted biological efficiency. Adherence to the methodology of choosing the type of pesticide application and selection of the type of spray is a key point in optimizing the rational use of chemical plant protection products, which requires a detailed study from the standpoint of both efficiency and safety. Control over compliance with the recommendations should be included in sanitary-hygienic and sanitary-ecological monitoring.

Seismological observations on the 2019 March 21 accidental explosion at Xiangshui chemical plant in Jiangsu, China

SUMMARY On 2019 March 21, an explosion accidentally occurred at a chemical plant in Xiangshui, Yancheng City, Jiangsu Province, China. Using broad-band digital seismic data from East China, South Korea and Japan, we investigate properties of the Xiangshui explosion as well as two nearby chemical explosions and four nearby natural earthquakes in Jiangsu Province, East China. From Lg and Rayleigh waves recorded by regional networks, both body wave magnitude mb (Lg) and surface wave magnitude Ms (Rayleigh) are calculated for these events. The magnitudes of the Xiangshui explosion are mb (Lg) = 3.39 ± 0.24 and Ms = 1.95 ± 0.27, respectively. Both the empirical magnitude–yield relation for buried explosion and empirical yield–crater dimension relation for open-pit explosion are adopted for investigating the explosive yield. The result from the yield–crater dimension relation is approximately 492 ton, which is consistent with the ground truth and considerably larger than that from the buried source model. This also reveals that, for Xiangshui explosion, the explosion to seismic energy conversion rate is approximately one-third compared to a similar sized fully confined explosion. By comparing the body wave and surface wave magnitudes from explosions and nearby earthquakes, we find that the mb:Ms discriminant calculated at regional distances cannot properly distinguish explosions from natural earthquakes. However, the P/S spectral ratios Pg/Lg, Pn/Lg and Pn/Sn from the same data set can be good discriminants for identifying explosions from earthquakes.